The original spatstat package has been split into
several sub-packages.
This package spatstat.geom is one of the
sub-packages. It contains the
definitions of spatial objects (point patterns, windows, pixel images, etc)
and the functionality for geometrical operations (intersection, union,
shift, rotate, measure areas, nearest neighbour distance,
pairwise distances, distance transform, plotting, etc).
The reorganisation of spatstat into a family of packages is described
on the GitHub repository
spatstat/spatstat.